A multiple projector system can be used to superimpose images to realize benefits such as higher brightness, a flicker-free image and an image with largely reduced screen door effect. Current multiple projector systems require very accurate inter-projector (i.e. between projectors) image registration to a sub-pixel level to achieve a similar image sharpness that can be realized from a single projector system. Current multiple projection systems that use warping engines to warp one projected image onto another projected image may do so within less than one pixel accuracy. However, image registration accuracy can degrade from system measurement error, optical non-uniformity, thermal drift over time and projector mechanical vibration. The problems can be exacerbated when projecting images are of resolution such as 4096×2160 (4K) or higher, which may need to be superimposed with a finer spatial alignment accuracy.
Another problem that may lead to image degradation in superimposed images can occur when warping one image to match another, which can have a limitation in image quality caused by digital pixel resampling. Image degradation caused by digital image resampling can make the image appear softer, less sharp because of more or less high frequency information loss during the resampling.
When even more projected images are superimposed from projectors in a multi-projection to further increase the dynamic brightness range of the superimposed image, the accuracy of alignment between the projected images can become more challenging. In such systems, the image of the superimposed images may suffer from alignment degradation more easily, and limit the potential to be realized with the increased number of projectors in a multi-projection system, in particular if projected images are from projectors that have a different image projection resolution.
Systems and methods are desirable that can tolerate a greater degree of image alignment error of superimposed projected images yet allow the perceived superimposed image to have the same image quality as if projected from one projector.